1. Field of the Invention
The present invention relates to a manufacturing method of an ink jet recording head, and to an ink jet recording head manufactured by the manufacturing method. In particular, the present invention relates to a manufacturing method of an ink jet recording head equipped with an orifice plate made of a resin including silicon, and to an ink jet recording head manufactured by the manufacturing method.
2. Related Background Art
An ink jet recording head applied to an ink jet printing system is generally equipped with a discharge port (orifice) of a fine liquid (ink), a liquid flow path and a liquid (ink) discharge pressure generation portion formed in a part of the liquid flow path.
Various methods have conventionally been proposed as a method for producing such an ink jet recording head as a fine structure like this.
Among them, there is a method which the present assignee has disclosed in Japanese Patent Application Laid-Open No. H05-330066. In the method, a resin has been formed as a shape member at a position where a nozzle flow path is formed on a substrate, and a resin which is not dissolved by the shape member is coated on the resin as the shape member. Then, the coated resin is cured. Furthermore, a nozzle pattern is formed on the surface of the insoluble resin (i.e. a nozzle constituting member) opposed to a material to be printed by means of a resin having a high oxygen plasma resistance property, and the nozzle constituting member is etched by the method of dry etching by the oxygen plasma by using the nozzle pattern as a mask to form a nozzle.
The above-mentioned method has advantages that the method does not need any cutting process of the surface of the orifice, and that the method does not need any adhesion by means of an adhesive, and further that the method can easily control the length of an ink flow path and the length of the orifice portion. The selectivity of materials is also wide in the method, and consequently the method is superior one in utility.
Now, in an ink jet recording head, there is the case where tantalum (Ta) or the like is used as a protective film for protecting a heating resistor provided on the surface of a substrate. For further improving the adhesion property to the substrate to which such a protective film is formed, a silane coupling agent or the like is sometimes mixed into the resin of the nozzle constituting member in consideration of an ink resistance property.
Accordingly, when the above-mentioned method was implemented by adopting a resin including silicon as the nozzle constituting member, columnar dregs were found. The columnar dregs easily remained by adhering to the wall of a flow path or the edge portion of a discharge port at the time of the removal of the shape member. The columnar dregs hinder the flow of ink in the flow path or make the discharge direction of the ink at the discharge port unstable at the time of discharging the ink. In particular, the diameter of the discharge port of a recording head has recently been required to be smaller (within a range from several to several tens μm) for realizing the improvement of picture quality. Consequently, it is apprehended that the adoption of the above-mentioned manufacturing method to such a recording head would exert an undesired influence upon the yield of products.